Byzantium

Byzantium was an ancient Greek colony that later became Constantinople and later Istanbul. Byzantium was colonized by Greeks from Megara in 657 BC, with the city being named for King Byzas. It was mainly a trading city due to its location at the Black Sea's only entrance, and it was conquered by Darius I in 513 BC. It was besieged by Greek forces during the Peloponnesian War, and it was conquered by Sparta in 411 BC and by Athens in 408 BC. The city was later absorbed into the Roman Republic and the Roman Empire, and the city was nearly destroyed in 196 AD during a siege by Septimius Severus after the city sided with Pescennius Niger. Septimius Severus went on to rebuild the city, which quickly regained its former prosperity. In 330 AD, Constantine the Great refounded the city as the Roman capital, and it was renamed to "Constantinople" after his death.